Reading unit for small holes



Dec. 4, 1951 C. D. LAKE ET AL Filed April 26, 1950 5 Sheets-Sheet l 45 Z5 j g Y 2 7 ,,2 i E;

INVENTORS Mam ATTO R N EY Dec. 4, 1951 c. D. LAKE ETAL 2,577,083

READING UNIT FOR SMALL HOLES Filed April 26, 1950 3 Sheets-Sheet 2 INVENTORS CL/I/R 0. LAKE BY WESLEY glgAF/ ATTORNEY Dec. 4, 1951 c. D. LAKE EIAL 2,577,083

READING UNIT FOR SMALL HOLES Filed April 26, 1950 3 Sheets-Sheet 3 msumr/m/ CARD CYCLE INVENTORS 8 CLAIR D. LAKE l E. WESLEY P l i I BY wl w ATTORNEY Patented Dec. 4, 1 951 READING UNIT FOR SMALL HOLES Clair D. Lake, Binghamton, and Wesley Pfafi,

Endicott, N. Y., assignors to International Business Machines Corporation, New York, N. Y., a.

corporation of New York Application April 26, 1950, Serial No. 158,094

3 Claims.

This invention relates to a device for sensing perforations in record cards or tape form of card and more particularly to a device for sensing such designations while the record cards, or tapes are in motion through the card or tape feeding mechanism of well known accounting and statistical machines.

The principal object of the invention is to provide an improved sensing device wherein the sensing of a perforation effects closure of contacts for controlling machine operation.

A more specific object of the invention resides in the novel arrangement of elements comprising the sensing device, in which a cam controlled bell crank operates an actuator through mechanical means, said actuator in turn guiding a spring contact member to an electrical circuit closing position.

Other objects of the invention will be pointed out in the following description and claims and illustrated in the accompanying drawings, which disclose, by way of example, the principle of the invention and the best mode, which has been contemplated, of applying that principle.

In the drawings:

Fig. 1 is a detail view of the improved sensing device shown in relation to a perforated record card or tape at the beginning of the first cycle point.

Fig. 2 is a position view of the elements in the first cycle point as the card is tested for perforations.

Fig. 3 is a position view of the elements in the first cycle in which a perforation is sensed by the bell crank finger.

Fig. 4 is a position view of the elements as the first cycle point draws to a close.

Fig. 5 is a position view of the elements at the end of the first cycle.

Fig. 6 is a position view of the elements at the beginning of the second cycle point in the absence of a perforation in the record card or tape.

Fig. 7 is a position view of the elements in the second cycle in which a perforation is sensed by the bell crank finger.

Fig. 8 is a chart relationship of contact and cycle point timing.

General description of the device Referring to the drawing, the record card feeding mechanism is diagrammatically represented by a pair of feeding rollers B which advance record card or tape Ii] toward the left with a continuous movement across a supporting plate i l. The card or tape [6 has perforations [2 arranged in the usual columns and rows according to the data their location represents.

In line with each column of perforations I2 is a sensing finger I3 united with bell crank [4 which is pivoted on a pin l5 which in turn is secured to base plate [6. Bell crank M has a tooth ll formed thereon and a bifurcated portion having contact arms I8 and IS. A spring extending between the bell crank l4 and stationary pin 2| urges said bell crank in a counterclockwise direction about pivot pin l5.

Ratchet cam 22 mounted on shaft 45 is rotated continually in a counterclockwise direction and its speed is synchronized with the movement of card I!) as it passes underneath the sensing finger IS. The ratchet portion of cam 22 comprises teeth 23, the number of which depend entirely upon the code being used and can be designed to accommodate any number or com binations of holes applying to a specific code. The distance L between successive holes of card It is such that each time a hole passes the sensing finger l3, a tooth 23 passes bell crank tooth H. A continuous cam surface 24 extends between the endmost teeth 23 of said ratchet portion of cam 22 and serves to keep the tooth ll of bell crank l4 out of engagement with cam teeth 23 thereby maintaining said bell crank in an inoperative position between card cycles. The interval between the lowest perforating rows of successive cards is termed a cycle of operation of the machine.

An interposer 25 is positioned slightly above bell crank l4. Said interposer comprises a bifurcated end portion having arms 51 and 52 and an opposite end portion having a slot 26 which engages a stationary pivot pin 33. Spring 34 extending between the interposer 25 and stationary pin 35 urges said interposer to move to the left, as viewed in Figs. l-7, until interference with pivot pin 33 occurs, thereafter the interposer is urged in a clockwise direction until the bell crank arms l8 and I9 are engaged by interposer contact surfaces 2'1, 28 or 29. Arms 5i and 52 are provided with contact surfaces 39, 3| and 32 for engaging and positioning a latch member 36.

Latch member 36 is positioned to the right of interposer 25 and pivoted on stationary pin 31. The upper portion of said latch member has a cam surface portion 38 which engages an actuator 38. Said actuator is triangular in shape having a base portion 4| with a slot therein and legs 42 and 43. At the junction point of the base 4| and leg 42, it is pivoted to a stationary pin 41. An insulated block 49 is attached at the junction point of legs 42 and 43 and serves to support the free end of a spring contact member 40, pivotally anchored to an input terminal 48. When actuator 38 is displaced ina counterclockwise direction about pin 47, insulated block 9 moves springcontact member 49 against output terminal 44 thereby completing an electrical circuit between input terminal 4-8 and output terminal .44. operation, actuator 38 is controlled by latch member 36 which in turn is positioned: by the interposer as a result oflensasgement with,

bell crank l4.

By virtue of its position and its contact sur-.

untila positionis-reached' where no hole appears.

Operation of. the device Referring-now to-Fig; 1, as: the position of the 'card' related to the first cycle point is being tested,:the tooth l'l'ofbell crank l4 engages the continuous surface portion 24 of ratchet cam 22, which is rotated continually in a counterclockwise direction, thereby maintaining said. bell crank in its normalinoperative position. With bell crank It in sucha position, arm l9 engages interposer surface 29 and latch member 36 lies in a substantially vertical plane with its upper cam portion. 39 seatedi in slot a-fi of actuator 38. The free end of spring contact member rests upon insulation block 49 which is positioned a short distancefrom contact terminal 44.

Asbell crank tooth ll drops off the continuous surface portion 24 ofcam 22, bell crank 14 is urged in a counterclockwise direction, about pivot pin E35, by spring 20. In the absence of a perforation at this time, sensing finger l3 rides on the surface of record It and bell crank 22' assumes the position. shownin Fig. 2'. (Wherein it is seen that under the influence ofsprings 34 :and20, belicrank M? is reclosed and 25; isshifted,

etc. while maintaining l9 in'2,9.).

However, if a perforation is sensed by finger t3, bell crank I4 is permitted greater-counterclockwise displacement-than"allowed by the absence of the hole in the card thereby enabling interposer 25, urged byspring 34, to move'to its .left, until interference with pivot pin 33 by: a side ofrslot 26: occurs asshown in Fig. 3. ,Thereafter, aqslightcounterclockwise rotation of said interposer 25follows,as bell crank arm. l9 slides from contact with interposer contact; surface 29 to a new position in which arm l9 engages surface 23, arm=l8- engages surface 21 and contact surface 3! is below the level of surface-50. Concurrently, interposer:contactsurface 32,- is placed in a tentative interfering position with latch member 38 as surface-3| assumes a non-interfering position with said latch member.

As the cycle point advances, ratchet cam 2-2 again cooperates with tooth H to restore in a clockwise directionthe bell crank l4, and inter- For, its. 7

poser 25 is in turn displaced to the right because of the pressure of arm l9 against contact surface 28. Concurrently, interposer 25 is displaced slightly in a counterclockwise direction as a result of the camming action between arm !8 and contact surface 21.

Referring now to Fig. 4, the movement of interposer 25 at surface 32 causes latch member 36, pivoted about pin 31, to be'displaced in a clockwise direction. Cam surface 39 of latch member 36 moves out of actuator slot 6 to displace actuator 38 counterclockwise about its pivot pint! andguide spring contact member to into contactwith electrical output terminal it. Thus,

1 an electrical impulse may be passed from input terminaldfl through contact member 13 to the fixed output terminal 44.

Referring now to Fig. 5, as the cycle point advancesthe continued clockwise rotation of bell crank l4 causes interposer 25 to be further displaced counterclockwise, by means of arm 18 cooperating with-contact surface 21, to a position in which arm t9 engages but; does not lie seated in surface 29; Then, interposer 25 is urged to the left by spring 3i and a counterclockwise displacement takes place until surface 23. isbroughtinto complete contact with finger 1 t9. At the end of the cycle point, latch member 36, actuator 38 and spring contact member lt remain in their displaced positionsand contact surface 32 of interposer 25 is therefore unable to engage latch member 36 for the following cycle point.

.Referring now to'Fig. 6, in the absence of a perforation in, thecard at'the beginning of the second cycle point, as tooth ll drops ofi cam tooth 23, bell crank 1 dis urgedin a counterclockwise direction by spring 29 as previously ex,- plained. Concurrently, interposer E5, urged by spring 3 2; is displaced counterclockwise as arm is applies pressure'to contact surface23. This movement of said interposer 25 enables surface 33 tolmove, from beneath surface 5% and brings surface 3! above the level of surface 5! so that it is in a position to engage latch member 35 upon a displacement to the right of the interposer 25 and thereby restore actuator 38 to the circuit breaking position.

However, if av perforation exists in the card M1 at the time the second cycle point is being tested, bell crank i a is permitted a greater counterclockwisedisplacement than allowed by the absence of a hole in card it). The differential is displacement enables interposer 25 to assume an position wherein arms i3 and L9 of hell crank, Mare in contact with surfaces 2? and Etrespectively of said interposer. In this arrangement of elements, as shown in, Fig. '7, surface 391s below surface of latch; member 35, therefore-surface, 3 I will not cooperate with said lat-ch member in thelensuing operation: of interposer 25 to move it counterclockwise until cam: surface 39 is again seated in actuatorslotfi and spring contact it has broken contact with terminal it.

As tooth: l1 cooperates with-a tooth 23 ofcam 22, bellcrank Hi moves clockwise and in turn interposer 25 is moved to the right and counter clockwise by theaction of arms is and lQ-working against contact surfaces 2? and 2-8 respectively. During this action of interposer 23 no motion is impartedtolatch member St for the reasons mentionedabove. Thus it is, seen that at the end of thesecond cycle point, elements 3%, 38 and it, remain in their displaced positions and contact betweenspring contactmember it andoutnutterminal 4.41s maintained.

Referring now to Fig. 8, the contact duration of contact member as and output terminal 44 is substantially equivalent to the duration of one cycle point for a single perforation in the card. In the case of two adjacent perforations or more, contact duration between said members is uninterrupted between the cycle point and duration remains constant until a cycle point position is reached wherein no perforation appears.

While there have been shown and described and pointed out the fundamental novel features of the invention as applied to a preferred embodiment, it will be understood that various omissions and substitutions and changes in the form and details of the device illustrated and in its operation may be made by those skilled in the art, without departing from the spirit of the invention. It is the intention, therefore, to be limited only as indicated by the scope of the following claims.

What is claimed is:

1. A record sensing mechanism, comprising a sensing element normally biased into sensing relationship with respect to a record having a series of spaced index point positions, means for advancing said record, to cause the positions to pass the sensing element in successive order, a circuit closing device, a power element effective to cause the sensing element to sense the positions in succession and effective further upon sensing a perforation in any position, to close the circuit closing device through the sensing element and reopen it during the sensing of the next succeeding position, and means effective in response to the presence of a perforation in said succeeding position for preventing the reopening of said circuit closing device, whereby the sensing of two holes in succession results in continued closure of said closing device for a period equal to that required for two successive full displacements and restorations of said sensing element and a sensing of the next following position.

2. A sensing device for a perforated record card comprising a sensing bell crank having a sensing finger portion and a tooth portion, a

continually rotating cam provided with a continuous surface portion and a ratchet portion, spring means for biasing the bell crank tooth portion against said continuous cam surface, said tooth portion dropping on" said continuous surface at a predetermined point in the machine cycle causing the bell crank sensing finger to rest upon the surface of a moving card in which perforations are located to pass said sensing finger, occurrence of a perforation at the sensing finger causing the finger to drop into the perforation and a displacement of the bell crank, a spring contact member, an actuator for guiding said spring contact member to a circuit closing position, continued rotation of said cam causing the ratchet and the bell crank tooth portion to cooperate to efifect a restoring displacement of said bell crank, and means operable by the bell crank for positively activating said actuator, comprising an interposer with bell crank connecting surfaces and a latch member having a cam portion engaging the actuator, said interposer positioning the latch member in cooperation with a bell crank displacement, the latch member in turn activating said actuator.

3. In a device of the class described, a sensing element having a sensing finger portion and a tooth portion, means for moving a record having a series of spaced index point positions to pass said sensing finger with the index positions in successive order, a spring contact member, an actuator for guiding said spring contact member to a circuit closing position, means for cooperating with said sensing element tooth portion to cause the sensing finger to sense the positions in succession and effective further upon sensing a perforation in any position, to actuate said actuator thereby closing a circuit and restore said actuator during the sensing of the next succeeding position whereby said circuit is opened, and means eifective in response to the presence of a perforation in said succeeding position for preenting the restoring of said actuator, whereby the sensing of two holes in succession results in continued closure of said circuit for a period. equal to that required for two successive full displacements and restorations of said sensing element and a sensing of the next following position.

CLAIR D. LAKE. WESLEY PFAFF.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,516,772 La Boiteaux Nov. 25, 1924 2,093,731 La Boiteaux Sept. 21, 1937 2,490,346 Furman Dec. 6, 1949 

